Field
Implementations of the present disclosure generally relate to forming protective layers on mechanical components, and more particularly, to electro-chemically forming coatings such as aluminum or aluminum oxide on semiconductor processing equipment.
Description of the Related Art
Conventionally, semiconductor processing equipment surfaces include certain coatings thereon to provide a degree of protection from the corrosive processing environment or to promote surface protection of the equipment. Several conventional methods utilized to coat the protective layer include physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma spraying, aerosol deposition, and the like. However, these conventional methods are unable to satisfactorily coat semiconductor equipment, especially in areas having small holes or plenums, such as showerheads. Some other techniques such as anodization of the substrate and PEO coatings can form a barrier layer inside the holes, however, these barrier layers include inherent porosity. The porosity of these layers can trap halides therein, and release the halides during processing thus causing undesired contamination.
Therefore, there is a need for improved deposition methods for protective coatings.